The forming behaviour of an Al–Cu–Mg alloy (Al 2024-T351) has been studied by processing maps and
microstructural characterization. Torsion tests were conducted in the range 278–467 ◦C, between 2.1 and
25.6 s−1. Stress–strain curves obtained from the experiment data were fitted using the Garofalo equation
to obtain the constitutive parameters, obtaining a stress exponent of 6.1 and an activation energy of
180 kJ/mol. Electron backscatter diffraction (EBSD) was employed to characterize the microtexture and
microstructure, before and after torsion testing, to evaluate the microstructural changes and instability
phenomena. A peak ductility of the Al 2024 alloy was found at about 400 ◦C at all strain rates considered.
According to the processing maps and microstructure observation, the optimum hot deformation
condition for the Al 2024 alloy is in the range 360–410 ◦C and 2.1–4.5 s−1. Under these favourable conditions
a uniform and fine grain size is obtained by extended dynamic recovery (DRV), which leads to the
formation of subgrain boundaries that progressively transform at large strains into new high angle grain
boundaries